Travel agencies have blasted the new reservation system of Cathay Pacific Airways and Dragonair, saying ticket redemption and free upgrade services are still severely disrupted one month after the service was meant to be up and running.

The hotline for the Marco Polo Club, Cathay's frequent flyer membership programme, has been overloaded over the past month, leading to huge delays in responding to passenger requests, agencies complained, with some saying it took as long as two weeks to get through to the hotline to confirm a booking.

Suzanna Chan, a local travel agent, said the Macro Polo hotline was so busy that she had to keep on dialling in for customers outside office hours. 'If my client is a green card holder [the lowest ranking of Marco Polo Club], the system will automatically cut off the line,' she said. 'They will only handle the request for gold card holders or up.'

Anna Kwan, another travel agent, also said she could not change a flight for her client because the hotline had been jammed for several days. 'My client kept asking me for updates which I don't have,' she said. 'My client is very angry and is blaming me.'

One frustrated passenger also criticised the system. 'When I tried to redeem my bonus points, the so-called Asia Miles, last month, I sat in on endless recordings waiting to speak to an agent, only to be kicked off the system. I've lost faith in the system,' said the passenger, who is a Marco Polo Club member.

Cathay said it was working to fix the problem as quickly as possible, but it would take some time before service was back to normal.

'We have recently undergone the largest system change in our history ... we have experienced some teething problems,' a Cathay spokesman said. 'We do expect increased call volumes and expanded hold times at our call centres for a while longer, even though staff are working extended shifts.'

Marco Polo Club last Friday sent a letter of apology to members for the service disruptions over the month. 'Please accept our sincere apologies for the recent increase in call waiting and handling times and e-mail response times,' it said in an e-mail.

Cathay said progress had been made, particularly in improving the stability of online service.

The airline suggested that passengers make reservations, flight award redemptions and changes to itinerary online instead of calling the service centres. However, travel agents said that option was closed to agents who could only change passengers' itineraries by phone.